import { isClient } from './is';

export type ResizableElement = CustomizedHTMLElement<{
  __resizeListeners__?: Array<(...args: unknown[]) => unknown>;
  __ro__?: ResizeObserver;
}>;

const resizeHandler = (entries: ResizeObserverEntry[]) => {
  for (const entry of entries) {
    const listeners = (entry.target as ResizableElement).__resizeListeners__ || [];
    if (listeners.length) {
      listeners.forEach(fn => {
        fn();
      });
    }
  }
};

export const addResizeListener = (
  element: ResizableElement,
  fn: (...args: unknown[]) => unknown,
) => {
  if (!isClient || !element) return;
  if (!element.__resizeListeners__) {
    element.__resizeListeners__ = [];
    element.__ro__ = new ResizeObserver(resizeHandler);
    element.__ro__.observe(element);
  }
  element.__resizeListeners__.push(fn);
};

export const removeResizeListener = (
  element: ResizableElement,
  fn: (...args: unknown[]) => unknown,
) => {
  if (!element || !element.__resizeListeners__) return;
  element.__resizeListeners__.splice(element.__resizeListeners__.indexOf(fn), 1);
  if (!element.__resizeListeners__.length) {
    element.__ro__?.disconnect();
  }
};

export const triggerWindowResize = () => {
  const event = document.createEvent('HTMLEvents');
  event.initEvent('resize', true, true);
  (event as any).eventType = 'message';
  window.dispatchEvent(event);
};
